Method, process and system for recycling an asphalt-based roofing material

ABSTRACT

The present disclosure provides a method, process and system for recycling an asphalt-based roofing material. In particular, the method, process and system are capable of removing and recovering an aggregate product, fiber product and an asphalt product from the asphalt-based roofing material. The aggregate, fiber and asphalt products each may be reused in a variety of applications.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional of U.S. patent application Ser. No.17/681,407, filed Feb. 25, 2022, which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to methods, processes andsystems for the recycling of asphalt-based roofing materials. Inparticular, the present disclosure generally relates to methods,processes and systems to separate the constituents of an asphalt-basedroofing shingle and recover and reuse such constituents in variousapplications.

BACKGROUND

A significant amount of unwanted material is generated from themanufacture, installation and removal of asphalt-based materials, suchas roofing shingles. For example, an average residential roof removalgenerates 1-3 tons of roofing shingles, depending on whether the oldroof consisted of 1 or 2 layers. All this adds up to an estimated totalof approximately 13.5 million tons of torn-off shingles every yearnationwide in North America, plus an additional 1 million tons of scrapgenerated by the shingle manufacturing process. This is a huge amount ofunwanted material destined for already overcapacity landfills,especially since torn-off roofing shingles take at least 300 years tobreak down and as such some jurisdictions are increasing disposal fees,limiting disposal limits to very low percentages or banning completely.Moreover, roofing shingles cannot be composted and burning orincineration is not recommended, as it may result in the emissions ofgases hazardous to human health. Since the materials in roofing shinglesare similar to those materials used in hot mix asphalt cement and otherroad applications, unwanted roofing shingles have been identified as amaterial that may be diverted from landfill disposal and recycled andreused, however use in road applications is limited to very lowpercentages in some jurisdictions or completely banned in others.

A roofing shingle is typically made up of different materials, includingcellulose (paper) or a fiberglass mat, an asphalt coating and a layer ofaggregate granules dispersed on the coating. Developing technicallyviable and cost-effective recycling processes has proven to bechallenging since these materials are difficult to break down/separateand therefore typically require complex process steps or equipment. Forexample, the asphalt and aggregate strongly adheres to one anothermaking their separation difficult. A further problem associated withefforts to recycle these materials concerns the difficulty in shreddingthe shingles on a bulk basis. Because of their high granular materialcontent, roofing shingles act like large pieces of sandpaper and assuch, large piles of roofing shingles are extremely difficult to drag,flow, separate, or handle. Additionally, recycling of roofing shinglesnormally requires modification to standard grinding, screening,separation and dust control equipment in order to reach the desired enduse products.

Some past recycling processes have used milling machines, such asrolling mills, bag mills, hammer mills, saw mills, etc. to produce arecycled roofing material which can only be used in road construction oras other similar “filler” material. Other processes have used a solventto break down the roofing shingle, for example, U.S. Pat. No. 8,789,773discloses a process, in which a solvent is first added to anasphalt-based material to form a mixture containing asphalt dissolved insolvent and a solids material. The solids material can be separated outby centrifugation or filtration while the asphalt dissolved in solventcan be fractionally distilled to separate the heavier asphalt phase fromthe lighter solvent phase. In WO 2020/041347, a process is disclosedthat includes contacting a roofing shingle with a petroleum chemical ina screened tubular rotating apparatus to separate asphalt from the sandand fiberglass. U.S. Pat. App. Publ. No. 2019/0256783 also discloses aprocess whereby roofing shingles are placed in a dissolution vessel anda solvent stream is added to the vessel to dissolve the asphalt underagitation to yield a solids rich stream and a solvent and bitumen richstream which can be passed through a flash drum to yield a solvent richstream and a bitumen rich stream. Finally, U.S. Pat. No. 4,222,851discloses a process in which roofing shingles are repeatedly washed withsolvent and the solvent and asphalt are subsequently separated from oneanother in first and second stage evaporators.

Nevertheless, there is a continuing need to provide improved methods andprocesses in which torn-off roofing shingles and shingle material whichis the by-product of the manufacture of new roofing shingles can berecycled and reused, thus avoiding landfill.

SUMMARY

According to an embodiment of the present disclosure, there is provideda method for removing aggregate from an asphalt-based roofing materialby: (a) contacting the asphalt-based roofing material with at least onepressurized stream of fluid to mechanically separate the aggregate fromthe asphalt-based roofing material and (b) agitating or pulsing theseparated aggregate, asphalt-based roofing material and fluid in aseparation tank to remove the separated aggregate from the asphalt-basedroofing material and fluid by density.

In some embodiments, the asphalt-based roofing material is contactedwith the at least one pressurized stream of fluid within the separationtank or externally in a separate vessel.

In some embodiments, the asphalt-based roofing material is contactedwith at least two pressurized streams of fluid. In some embodiments theat least two pressurized streams of fluid are opposed to one another.

In some embodiments, the fluid comprises water. In some embodiments, thefluid is at ambient temperature.

In some embodiments, the asphalt-based roofing material is pretreated tocrush or grind the asphalt-based roofing material.

In some embodiments, the method further comprises the step of recoveringthe separated aggregate. In some embodiments, least about 90 wt. % of atotal weight of aggregate originally present in the asphalt-basedroofing material is recovered as separated aggregate.

According to another embodiment, there is provided a method forseparating fiber from an aggregate-free asphalt-based roofing material,by: (a) mixing the aggregate-free asphalt-based roofing material with asolvent to form a slurry and (b) machine pressing or filter pressing theslurry in a fiber separator to separate fiber from the slurry andproduce an asphalt/solvent mixture and a fiber product. Theaggregate-free asphalt-based roofing material was obtained by contactingan asphalt-based roofing material with at least one pressurized streamof fluid to remove substantially all aggregate from the asphalt-basedroofing material.

In some embodiments, the solvent is selected from an aromatic solvent,an aliphatic solvent, an alcohol, an ether, a ketone, carbon disulfideand a mixture thereof. In some embodiments, a mass fraction of solventmixed with the aggregate-free asphalt-based roofing material is in arange of about 15-50 wt. % relative to the total weight of the slurry.

In some embodiments, the fiber separator is a rotary press, a beltpress, a hydraulic press, a piston press, a hydrocyclone or a screwpress.

In some embodiments, the aggregate-free asphalt-based roofing materialwas obtained by contacting an asphalt-based roofing material with atleast one pressurized stream of fluid to remove substantially allaggregate from the asphalt-based roofing material and drying theasphalt-based roofing material.

In some embodiments, the fiber product is substantially free of asphalt.

In still another embodiment, there is provided a method for recoveringan asphalt product from an asphalt/solvent mixture by: (a) passing theasphalt/solvent mixture through a solvent separator to separate theasphalt product from the solvent and (b) removing the asphalt from thesolvent separator. The asphalt in the asphalt/solvent mixture wasderived from an asphalt-based roofing material and is substantially freeof aggregate and fiber.

In some embodiments, the solvent separator is a distillation unit orevaporator. In some embodiments, solvent separator is a wiped filmevaporator. In some embodiments, the solvent comprises an aromaticsolvent.

In some embodiments, step (a) is performed at a temperature betweenabout 155° C. to about 165° C. and at atmospheric pressure.

In some embodiments, at least about 80 wt. % of a total weight ofasphalt originally in the asphalt-based roofing material is recovered asthe asphalt product.

In some embodiments, there is provided an asphalt product producedaccording to the above-described methods.

In still another embodiment, there is provided a system for producing atleast an asphalt product from an asphalt-based roofing materialcontaining a plurality of roofing shingles, the system comprising (a) anaggregate removal unit operable to remove substantially all aggregatefrom the asphalt-based roofing material to produce an aggregate-freeasphalt/fiber mixture, (b) a fiber separation unit operable to mix theaggregate-free asphalt/fiber mixture with a solvent to produce a slurryand to remove substantially all fiber from the slurry to produce anasphalt/solvent mixture and (c) a solvent separation unit operable toseparate substantially all solvent from the asphalt to produce anasphalt product.

In some embodiments, the aggregate removal unit comprises a separationtank configured to receive and combine the asphalt-based roofingmaterial and at least one or more pressurized streams of a first fluidand to agitate or pulse a mixture of aggregate, a second fluid and theaggregate-free asphalt/fiber mixture. In some embodiments, the aggregateremoval unit further comprises a dewatering or drying apparatusconfigured to remove moisture from the asphalt/fiber mixture.

In some embodiments, the fiber separation unit comprises a mixing tankconfigured to receive and combine the aggregate-free asphalt/fibermixture and a solvent and produce an asphalt/fiber/solvent slurry. Insome embodiments, the fiber separation unit further comprises a fiberseparator configured to receive the asphalt/fiber/solvent slurry andseparate fiber from the asphalt/fiber/solvent slurry and produce anasphalt/solvent mixture and a fiber product.

In some embodiments, the solvent separation unit comprises a solventseparator configured to receive the asphalt/solvent mixture and heat themixture to separate the solvent from the mixture and produce the asphaltproduct. In some embodiments, the solvent separation unit furthercomprises a condenser configured to recover the solvent separated fromthe mixture.

In some embodiments, the system further comprises a pretreatment unitcomprising a grinder operable to reduce the particle size of theasphalt-based roofing material and a feed system to deliver theasphalt-based roofing material to the aggregate removal unit.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention,

FIG. 1 is a schematic block diagram of a method for recycling anasphalt-based roofing material according to an embodiment of the presentdisclosure; and

FIG. 2 schematically illustrates a system for producing an asphaltproduct from an asphalt-based roofing material according to anotherembodiment of the present disclosure.

DETAILED DESCRIPTION

The following terms shall have the following meanings:

The term “comprising” and derivatives thereof are not intended toexclude the presence of any additional component, step or procedure,whether or not the same is disclosed herein. In order to avoid anydoubt, all compositions claimed herein through use of the term“comprising” may include any additional additive or compound, unlessstated to the contrary. In contrast, the term, “consisting essentiallyof” if appearing herein, excludes from the scope of any succeedingrecitation any other component, step or procedure, except those that arenot essential to operability and the term “consisting of”, if used,excludes any component, step or procedure not specifically delineated orlisted. The term “or”, unless stated otherwise, refers to the listedmembers individually as well as in any combination.

The articles “a” and “an” are used herein to refer to one or to morethan one (i.e., to at least one) of the grammatical objects of thearticle. By way of example, “a solvent” means one solvent or more thanone solvent. The phrases “in one embodiment”, “according to oneembodiment” and the like generally mean the particular feature,structure, or characteristic following the phrase is included in atleast one embodiment of the present disclosure and may be included inmore than one embodiment of the present disclosure. Importantly, suchphrases do not necessarily refer to the same aspect. If thespecification states a component or feature “may”, “can”, “could”, or“might” be included or have a characteristic, that particular componentor feature is not required to be included or have the characteristic.

The term “about” as used herein can allow for a degree of variability ina value or range, for example, it may be within 10%, within 5%, orwithin 1% of a stated value or of a stated limit of a range.

Values expressed in a range format should be interpreted in a flexiblemanner to include not only the numerical values explicitly recited asthe limits of the range, but to also include all of the individualnumerical values or sub-ranges encompassed within that range as if eachnumerical value and sub-range is explicitly recited. For example, arange such as from 1 to 6, should be considered to have specificallydisclosed sub-ranges, such as, from 1 to 3, from 2 to 4, from 3 to 6,etc., as well as individual numbers within that range, for example, 1,2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

The terms “preferred” and “preferably” refer to embodiments that mayafford certain benefits, under certain circumstances. However, otherembodiments may also be preferred, under the same or othercircumstances. Furthermore, the recitation of one or more preferredembodiments does not imply that other embodiments are not useful, and isnot intended to exclude other embodiments from the scope of the presentdisclosure.

The term “optional” or “optionally” means that the subsequentlydescribed event or circumstance may or may not occur, and that thedescription includes instances where said event or circumstance occursand instances where it does not.

The term “substantially free” refers to a composition in which aparticular constituent or moiety is present in an amount that has nomaterial effect on the overall composition. In some embodiments,“substantially free” may refer to a composition in which the particularconstituent or moiety is present in the composition in an amount of lessthan about 10 wt. % or less than about 5 wt. %, or less than about 4 wt.%, or less than about 3 wt. % or less than about 2 wt. % or less thanabout 1 wt. %, or less than about 0.5 wt. %, or less than about 0.1 wt.%, or less than about 0.05 wt. %, or even less than about 0.01 wt. %based on the total weight of the composition, or that no amount of thatparticular constituent or moiety is present in the respectivecomposition.

The term “substantially” means a proportion of at least about 60%, orpreferably at least about 70% or at least about 80%, or at least about90%, at least about 95 wt. %, at least about 97% or at least about 99%or more, or any integer between about 70% and about 100%. For example,removing substantially all of a component from a composition may be theremoval of at least about 60 wt. % or at least about 70 wt. %, etc. ofthe component from the composition.

The term “wt. %” means weight percent.

The term “integrated process” means a process where two or more relatedprocess steps of at least two separate industrial processes, which canbe separately performed, are combined, so that at least one process stepis common for the two processes. Moreover, in an “integrated process” asdefined herein streams, fractions and/or portions produced and/orobtained in one industrial process can be used in another industrialprocess thereby improving the overall process efficiently more than thesum of each individual process. The integrated process reuses certainmaterials and streams and reduces by-products that otherwise wouldrequire treatment. In other words, the term “integrated process” means acombination of at least two unit operations which exploits theinteractions between different units in order to employ resourceseffectively, improve energy efficiency, improve material balance,maximize profit and/or minimize costs. At least one of the two unitoperations receives material and/or energy, and may be dependent onthese, from the other unit operation. In an integrated process theinteractions between different unit operations are considered from theoutset, rather than having them optimized separately. Processintegration is not limited to the design of new plants, but it alsocovers retrofit design, for example new units to be installed in an oldplant, and the operation of existing systems.

The term “asphalt-based roofing material” as used herein may refer toany new or used material that is used in connection with roofing andthat contains a proportion of asphalt, such as for example, new or tornoff (used) roofing shingles (which may be organic or fiberglass), new orused roofing felt or tar paper, flat roof material (which may includefelt, aggregate and bitumen or asphalt sealant), unwanted material fromthe production of new roofing shingles or unwanted material from theinstallation of roofing shingles on residential or commercial buildings.In addition to asphalt, the asphalt-based roofing material may furtherinclude a proportion of aggregate and fiber. For example, a roofingshingle may include from about 45-55 wt. % aggregate, from about 20-30wt. % fiber and from about 20-30 wt. % asphalt, based on the totalweight of the roofing shingle.

The term “asphalt” may refer to any type of bituminous material suitablefor use on a roofing material or pavement, such as asphalts, tars,pitches, or mixtures thereof. The asphalt may be either manufacturedasphalt produced by refining petroleum or naturally occurring asphalt.The asphalt can be oxidized or non-oxidized. The asphalt may include anynumber of various additives and/or modifiers, such as inorganic fillersor mineral stabilizers, organic materials such as polymers, recycledstreams, and/or ground tire rubber.

The term “aggregate” may refer to solid particles having a range ofsizes including fine particles to relatively coarse particles, forexample sand, crushed stone, gravel, slag, or other mineral granules.

The term “fiber” as used herein may refer to a solid fibrous materialsuch as glass fiber or paper (cellulose) fiber. The term may refer to amat of interwoven fiber strands when present in roofing shingles, or toa mixture of individual strands and/or particles of fiber.

The term “asphalt/fiber slurry” as used herein may refer to a mixture ofasphalt, fiber (which may include fiber particles alone or partially orcompletely coated with asphalt), and a fluid.

The term “asphalt/fiber mixture” as used herein may refer to a mixtureof asphalt and fiber derived from an asphalt-based roofing material. Theasphalt/fiber mixture may include asphalt, fiber and fiber partially orcompletely coated with asphalt. The asphalt/fiber mixture may alsocontain a proportion of a fluid but which proportion is less than theproportion of fluid present in the asphalt/fiber slurry defined above.

The term “asphalt/fiber/solvent slurry” as used herein may refer to amixture of fiber carried by a mixture of asphalt and a solvent (or ablend of more than one solvent).

The term “asphalt/solvent mixture” as used herein may refer to a mixtureof asphalt and a solvent (or a blend of more than one solvent), wherethe asphalt may be fully or partially miscible with the solvent ordispersed within the solvent.

The present disclosure generally relates to a method and integrativeprocess for recycling an asphalt-based roofing material and to a systemfor producing an asphalt product from such an asphalt-based roofingmaterial. It has been surprisingly found that the method, process andsystem of the present disclosure can break down and effectively separatethe constituents of the asphalt-based roofing material (suchconstituents having been combined together to produce the asphalt-basedroofing material) using minimal equipment and without having to inputlarge amounts of energy. Thus, the methods, integrative process andsystem of the present disclosure are more economical and environmentallyfriendlier than state of the art methods, processes and systems.Additionally, because the constituents of the asphalt-based roofingmaterial are effectively separated from each other in high yields andpurities, they can be repurposed/used in a wide range of applications.Thus, the inventive method, integrative process and system of thepresent disclosure avoid the need of having to sanitarily dispose asubstantial amount of unwanted material generated during the shinglemanufacturing process or during the shingling or re-shingling of a roof.

With reference to FIG. 1 , a method 100 for recycling the asphalt-basedroofing material, which according to an embodiment includes at least aplurality of roofing shingles 102, is shown and may generally includesteps 104 to 108. In step 104, aggregate is removed from theasphalt-based roofing material mechanically and by density to produce anasphalt/fiber mixture 112 and an aggregate product 110. In someembodiments, the method may optionally include a step of mechanicallyreducing the size of the asphalt-based roofing material prior to step104. In some embodiments, the asphalt/fiber mixture 112 that is producedin step 104 is substantially free of aggregate. In step 106, a solvent114 is added to the asphalt/fiber mixture 112 to produce anasphalt/fiber/solvent slurry and the slurry is machine pressed to removefiber from the slurry to produce an asphalt/solvent mixture 118 and afiber product 116. In some embodiments, the asphalt/solvent mixture thatis produced in step 106 is substantially free of fiber or aggregate orfiber and aggregate. In step 108, the solvent is separated from theasphalt/solvent mixture 118 to produce an asphalt product 120. In someembodiments, the asphalt product 120 that is produced in step 108 issubstantially free of solvent or fiber or aggregate or solvent and fiberand aggregate. In further embodiments, the solvent that is separatedfrom the asphalt/solvent mixture in step 108 may be recovered and reusedin step 106.

According to another embodiment, a system 200 operable for performingthe method above to produce at least an asphalt product 218 from anasphalt-based roofing material containing a plurality of roofingshingles 202, is generally shown in FIG. 2 . The system 200 may becontrolled by a controller (not shown) configured to control some or allof the operations described below. In particular, the controller may beconfigured to execute computer code for performing the operationsdescribed herein. In this regard, the controller may comprise aprocessor that may be a microprocessor or a controller for controllingthe overall operation thereof. In one embodiment the processor may beparticularly configured to execute program code instructions related tothe functions described herein. The controller may also include a memorydevice. The memory device may include non-transitory and tangible memorythat may be, for example, volatile and/or non-volatile memory. Thememory device may be configured to store information, data, files,applications, instructions or the like. For example, the memory devicecould be configured to buffer input data for processing by theprocessor. Additionally or alternatively, the memory device may beconfigured to store instructions for execution by the processor.

The controller may also include a user interface that allows a user tointeract therewith. For example, the user interface can take a varietyof forms, such as a button, keypad, dial, touch screen, audio inputinterface, visual/image capture input interface, input in the form ofsensor data, etc. Still further, the user interface may be configured tooutput information to the user through a display, speaker, or otheroutput device. A communication interface may provide for transmittingand receiving data through, for example, a wired or wireless networksuch as a local area network (LAN), a metropolitan area network (MAN),and/or a wide area network (WAN), for example, the Internet. Thecommunication interface may enable the controller to communicate withone or more further computing devices, either directly, or via anetwork. In this regard, the communication interface may include one ormore interface mechanisms for enabling communication with other devicesand/or networks. The communication interface may accordingly include oneor more interface mechanisms, such as an antenna (or multiple antennas)and supporting hardware and/or software for enabling communications viawireless communication technology (e.g., a cellular technology,communication technology, Wi-Fi and/or other IEEE 802.11 technology,Bluetooth, Zigbee, wireless USB, NFC, RF-ID, WiMAX and/or other IEEE802.16 technology, and/or other wireless communication technology)and/or a communication modem or other hardware/software for supportingcommunication via cable, digital subscriber line (DSL), USB, FireWire,Ethernet, one or more optical transmission technologies, and/or otherwireline networking methods. Further, the controller may include variousmodules which may be configured to, in conjunction with the processor,direct operations for removing the aggregate from the roofing shinglesin the aggregate removal unit, separating the fiber in the fiberseparator unit and/or separating the solvent in the solvent separatorunit to ultimately produce the asphalt product as described herein.

As illustrated, the system 200 may include an aggregate removal unit204. The aggregate removal unit 204 is operable to perform step 104above and may include a separation tank 222 configured to receive andcombine the roofing shingles 202 and at least one or more pressurizedstreams of fluid 224. The separation tank 222 may also be configured toagitate or pulse a mixture of a fluid (which may be the same fluid asthe pressurized stream of fluid or a different fluid), the roofingshingles and aggregate that may be contained therein. The aggregateremoval unit 204 may further include a dewatering and/or dryingapparatus 228 configured to receive the mixture contained in theseparation tank 222 and to remove moisture from the mixture. Thus, aswill be described in more detail below, the separation tank 222 isconfigured to receive and combine the roofing shingles 202 and one ormore pressurized streams of fluid 224 and to agitate or pulse themixture of fluid, roofing shingles and aggregate to produce anasphalt/fiber slurry 226 and an aggregate product 210. The dewateringand drying apparatus 228 is configured to receive the asphalt/fiberslurry 226 and remove moisture from the asphalt/fiber slurry 226 toproduce an asphalt/fiber mixture 212. In some embodiments, the moisturethat is removed in the dewatering and drying apparatus 228 may berecovered and reused in system 200.

The system 200 may also include a fiber separation unit 206. The fiberseparation unit 206 is operable to perform step 106 above and mayinclude a mixing tank 232 configured to receive and combine themoisture-removed mixture from the aggregate removal unit 204 and aliquid. The fiber separation unit 206 may further include a fiberseparator 236 configured to receive the contents in the mixing tank 232and separate solids from liquids. Thus, as will be described in moredetail below, the mixing tank 232 is configured to receive and combinethe asphalt/fiber mixture 212 and a solvent 230 to produce anasphalt/fiber/solvent slurry 234. The fiber separator 236 is configuredto receive the asphalt/fiber/solvent slurry and separate fiber from theasphalt/fiber/solvent slurry 234 to produce an asphalt/solvent mixture216 and a fiber product 214.

Finally, the system 200 may include a solvent separation unit 208. Thesolvent separation unit 208 may be used to perform step 108 above andmay include a solvent separator 238 configured to receive a mixture ofliquids and heat the mixture to separate the liquids in the mixture.Thus, as will be described in more detail below, the solvent separator238 is configured to receive the asphalt/solvent mixture 216 and heatthe mixture to separate the solvent from the mixture to produce anasphalt product 218. In some embodiments, the solvent separation unitmay further include a condenser configured to condense and recover thesolvent separated from the mixture so that it can be reused in thesystem 200.

In a further embodiment, the system 200 may optionally include apretreatment unit (not shown). The pretreatment unit may include agrinder that is operable to crush or grind the asphalt-based roofingmaterial as needed based on production and availability in order toreduce the roofing material to a desired particle size (for e.g., to amaximum of less than about 1 inch). In one embodiment, the particle sizeis screened to ¾ inch minus (i.e., ¾ of an inch or less). It should benoted that the particles are generally irregularly shaped. In someembodiments, the asphalt-based roofing material may first be cleaned ofnails and other debris by hand or by using a magnet before being sent tothe grinder. In other embodiments, nails and debris maybe removed afterthe feed hopper or after first stage of separation. The pretreatmentunit may further include a feed system configured to receive theasphalt-based roofing material from the grinder and which may beinterlocked with other plant components and controlled by thecontroller. The feed system may include a feed hopper which may beequipped with a drive motor, a strainer (e.g., comprising one or morescreens), and one or more conveyors (e.g., comprising an auger). Thefeed system may be calibrated to regulate flow of the asphalt-basedroofing material to the aggregate removal unit 204 as controlled by thecontroller.

Removal of Aggregate (Step 104) in the Aggregate Removal Unit (204)

As described above, in step 104 aggregate is removed from the roofingshingles 102 to produce the aggregate product 110 and the asphalt/fibermixture 112. In the embodiment shown in FIG. 2 , this removal may beaccomplished in the aggregate removal unit 204 mechanically and bydensity by physically contacting the roofing shingles 202 with one ormore pressurized streams of fluid 224 in the separation tank 222 toseparate aggregate from the roofing shingles and by agitating or pulsingthe mixture of fluid, roofing shingles and separated aggregate containedwithin the separation tank 222. In other embodiments the roofingshingles may be physically contacted with the one or more pressurizedstreams of fluid 224 prior to the separation tank 222.

The separation tank 222 may be shaped, sized and configured to hold anysuitable volume of fluid and is also operable to agitate or pulse thefluid contained therein and therefore may include an inner cavity and amixing device. Examples of mixing devices include, but are not limitedto, vanes, paddles, blades, screw elements, or other elements of dynamicmixers such as rotating or co-rotating screw mixers, planetary anddouble planetary mixers, impellers, and the like or baffle elementswithin a static mixer, such as plates, helices, vanes, paddles, orblades, intended to disrupt laminar flow and cause mixing within thestatic mixer. In an embodiment, the mixing device is a is a movablepaddle or block that creates an up and down or side to side movementwithin separation tank 222 to pulse the fluid in the separation tank222. The separation tank 222 may be in fluid communication with one ormore sources of fluids (such as a holding or buffer tank) via one ormore conduits which supply the one or more pressurized streams (or jets)of fluid 224 to the separation tank 222. Each stream of fluid 224supplied to and received by the separation tank 222 may be the samefluid or a different fluid.

The roofing shingles 202 may be introduced into some, or all, of the oneor more pressurized streams of fluid 224 supplied to the separation tank222 by any suitable method. For example, the roofing shingles 202 may besupplied to a funnel or hopper as described above that is incommunication with some, or all, of the one or more streams of fluid224. The controller may control the amount of the roofing shingles 202which are contacted by a stream of fluid 224. Contact between theroofing shingles 202 and the streams of fluid 224 may be of sufficientforce to dislodge aggregate from the roofing shingles 202 such thataggregate is separated from the roofing shingles 202. In addition, theforce may be sufficient to dislodge asphalt that is adhered to andcoating the aggregate such that aggregate that is separated issubstantially free of adhered asphalt.

The elevated flow rate and/or pressure of the one or more streams offluid 224 entering the separation tank 222 may be sufficient to causecavitation of the fluid within separation tank 222. As is well known,cavitation is a phenomenon in which the local static pressure of a fluidis reduced to below the vapor pressure of the fluid causing theformation of small vapor filled cavities (or bubbles) within the fluid.Thus, one or more fluid conduits that supply the streams of fluid 224 toseparation tank 222 may be configured to produce Venturi effects via arelatively narrow or constricted section within the conduit followed bya wider section that is positioned close to the outlet. As the stream offluid 224 passes through the constricted section, the pressure of thefluid will decrease as the flow rate increases. The combination ofpressure and kinetic energy can create a cavitation cavern downstream ofthe constriction generating high energy cavitation bubbles. Thesecavitation bubbles may subsequently collapse, generating shockwaveswaves within the fluid. As these shockwaves contact roofing shingles 202within separation tank 222, a cavitation force is applied to roofingshingles 202 sufficient to separate aggregate from the otherconstituents of the roofing shingles 202. The cavitation force may alsobe sufficient to dislodge asphalt adhered to and/or coating theaggregate particles such that the aggregate is substantially free ofasphalt.

Further, each of the one or more fluid conduits may be positioned suchthat the outlet of each of the one or more conduits is generallydirected towards the outlet of another of the one or more conduits. Thismeans that one stream of fluid 224 exiting from one conduit will collidewith another stream of fluid 224 exiting from another conduit withinseparation tank 222. This may further increase the turbulent flow offluid 224 within separation tank 222 and may also increase contactbetween roofing shingles 202 and stream of fluid 224 to assist inseparating aggregate from the roofing shingles 202.

In one embodiment, the separation tank 222 may have one pair ofconduits, where the outlet of the first conduit may be generallydirected towards the outlet of the second conduit such that the streamof fluid 224 exiting through the outlet of the first conduit willcollide with the stream of fluid 224 exiting through the outlet of thesecond conduit.

In other embodiments, the separation tank 222 may have more than onepair of conduits where the outlet of the first conduit in each pair maybe generally directed towards the outlet of the second conduit in eachpair. For example, the separation tank 222 may have 2, 4, 6, 8, 10, 12or more pairs of conduits where the outlet of the first conduit in eachpair may be generally directed towards the outlet of the second conduitin each pair. Each of the pairs of conduits may be positioned atdifferent locations in separation tank 222, for example each pair ofconduits may be vertically spaced from the next pair of conduits.

In still other embodiments, in each of the pairs of conduits describedabove, the outlet of the first conduit may directly oppose the outlet ofthe second conduit in each pair. This may increase the contact betweenthe opposing streams of fluid, increasing the number and the force ofcollisions between the roofing shingles 202 and streams of fluid 224.

In a further embodiment, the separation tank 222 may include more thantwo conduits with outlets generally directed towards each other. Forexample, the separation tank 222 may have three conduits, where theoutlets of the first, second and third conduits are directed towardseach other. In other embodiments, separation tank 222 may have 4, 5 or 6or more conduits all having outlets directed towards each other.

In another embodiment, the separation tank 222 may have a singleconduit, where the outlet of the single conduit is generally directedtowards an impact surface such as a contact plate, or the inner surfaceof separation tank 222. The use of an impact surface other than theinner surface of separation tank 222 may be preferable to reduce wear ofthe inner surface of separation tank 222 caused by impact of the streamof fluid 224. The force of the stream of fluid impacting the contactplate may be of sufficient force to dislodge aggregate from the roofingshingles 202 and/or cause cavitation of the fluid within separation tank222 as described above.

In further embodiments, the separation tank 222 may have multiple setsof single conduits where the outlets of the single conduits aregenerally directed towards an impact surface. For example, theseparation tank 222 may have 2, 3, 4, 5, 6, 7, 8 or more sets of singleconduits where the outlets of the single conduits are generally directedtowards an impact surface.

In still other embodiments, for each impact surface in the separationtank 222 there may be more than one conduit where the outlet of eachconduit is generally directed towards the impact surface. For example,each impact surface may have 2, 3, 4, 5, 6 or more conduits where theoutlet of each conduit is generally directed towards the impact surface.

The separation tank 222 is further configured to agitate or pulse amixture of fluid, aggregate and roofing shingles contained therein.Agitation may be achieved by any known mixing device as described above,such as for example, by rotation of a paddle or impeller configured tocirculate the roofing shingles that have fallen towards the lower regionof the separation tank 222 (and into the fluid contained therein) in themixture in a generally upwards direction. By increasing the contact timeof the roofing shingles 202 and fluid via agitation or pulsing,separation of aggregate from the roofing shingles 202 may be furtherincreased in separation tank 222.

In one embodiment, the pressure of the one or more pressurized streamsof fluid 224 supplied to and received by the separation tank 222 mayrange between about 100 psi to about 150 psi, or about 105 psi to about145 psi, or about 110 psi to about 140 psi, or about 115 psi to about135 psi, or about 120 psi to about 130 psi. In an embodiment, the flowrate of the one or more pressurized streams of fluid 224 supplied to andreceived by the separation tank 222 may range between about 50 m³/hr toabout 100 m³/hr, or about 55 m³/hr to about 95 m³/hr, or about 60 m³/hrto about 90 m³/hr, or about 65 m³/hr to about 85 m³/hr, or about 70m³/hr to about 80 m³/hr.

In another embodiment, the separation tank 222 may be generallycylindrical and orientated vertically. In a specific embodiment, theseparation tank 222 may have an internal volume of about 10 m³ to about100 m³, or about 20 m³ to about 90 m³, or about 30 m³ to about 70 m³, orabout 40 m³ to about 60 m³.

The fluid supplied to and received by the separation tank 222 asdescribed above may be selected from a fluid or blend of fluids having alower specific gravity than the specific gravity of aggregate, suchthat, once the aggregate has been separated from roofing shingles 202,it will migrate towards the lower end or bottom of separation tank 222.An aggregate product 210 may then be removed from such lower end orbottom of the separation tank 222 and further processed or repurposed aswill be further described below. The fluid or blend of fluids may alsohave a specific gravity that is greater than the specific gravity of theremaining constituents of roofing shingles 202, namely a mixture ofasphalt and fiber, so that this mixture will migrate to the upper end ofseparation tank 222 for removal as an asphalt/fiber slurry 226.

Furthermore, in some embodiments, the fluid or blend of fluids describedabove may also be immiscible with asphalt so that the asphalt present inthe roofing shingles 202 is not lost through dissolution into the fluidor blend of fluids. For example, in one embodiment such fluid mayinclude a glycol, such as ethylene glycol and propylene glycol. Inanother embodiment, the fluid may include an alcohol, such as a straightor branched chain C₁-C₁₀ alcohol or mixture thereof. In anotherembodiment the C₁-C₁₀ alcohol is ethanol, n-propanol, isopropanol (IPA),n-butanol, propanol, or t-butanol. In yet another embodiment the fluidmay comprise dimethylformamide (DMF), acetonitrile, acetone,tetrahydrofuran dimethylsulfoxide (DMSO), methylethylketone (MEK), or anaromatic solvent such as benzene, methylbenzene (toluene),dimethylbenzene or ethylbenzene.

In one specific embodiment, the fluid supplied to and received by theseparation tank 222 via the one or more conduits comprises water. Apressurized stream of water may enter the separation tank 222 throughthe one or more conduits at a pressure ranging between about 100 psi toabout 150 psi or about 105 psi to about 145 psi, or about 110 psi toabout 140 psi, or about 115 psi to about 135 psi, or about 120 psi toabout 130 psi. In an embodiment, the flow rate of the stream of watermay range between about 50 m³/hr to about 130 m³/hr, or about 55 m³/hrto about 125 m³/hr, or about 60 m³/hr to about 120 m³/hr, or about 65m³/hr to about 115 m³/hr, or about 70 m³/hr to about 110 m³/hr or about75 m³/hr to about 105 m³/hr or about 80 m³/hr to about 100 m³/hr orabout 85 m³/hr to about 95 m³/hr. The pressure and flow rate may beselected so they are sufficient to cause cavitation in the separationtank 222.

In an embodiment, the fluid contained within the separation tank 222and/or the one or more streams of fluid 224 contacting the roofingshingles 202 are at ambient temperature. Aside from the lower energyinput required, performing step 104 at ambient temperatures mayadvantageously assist in the separation of aggregate from the roofingshingles 202 since at lower temperatures, the roofing shingles 202 tendto be more brittle (and less ductile) allowing the aggregate to separatefrom the roofing shingles 202 more easily.

In a further embodiment, the fluid contained in the separation tank 222and/or the one or more streams of fluid 224 contacting the roofingshingles 202 may be at an elevated temperature, i.e. a temperature thatis greater than ambient temperature. The elevated temperature may beattained by any suitable method known in the art. For example, theseparation tank 222 and or one or more conduits may include heatingcoils or heat traces. Alternatively, the streams of fluid 224 suppliedto the separation tank 122 through the one or more conduits may bepreheated to an elevated temperature relative to the fluid contained inseparation tank 222.

As described above, aggregate separated from the roofing shingles 202may migrate towards the lower end or bottom of the separation tank 222during agitation. The lower end of the separation tank 222 may have atapered frustoconical shape such that separated aggregate is channeledtowards the lower end of the separation tank 222 and recovered from theseparation tank 222 as an aggregate product 210. The aggregate product210 that is recovered may be dewatered and/or dried using any suitablemeans known to those skilled in the art, such as by passing theaggregate product 210 over a vibrating screen/shaker deck or by airdrying. In some embodiments, moisture that is removed during drying maybe collected, filtered or desilted in one or more purification steps andthen recycled back to the separation tank 222.

The separation of aggregate from the roofing shingles 202 during step104 may be highly efficient such that substantially all of the aggregateoriginally present in the roofing shingles 202 is recovered fromseparation tank 222 as the aggregate product 210 and therefore theroofing shingles 202 remaining in separation tank 222 are substantiallyfree of aggregate, i.e., aggregate-free asphalt-based roofing shingles.According to one embodiment, at least about 90 wt. % of the total weightof aggregate originally present in the roofing shingles 202 is recoveredas aggregate product 210. In other embodiments at least about 91 wt. %,or at least about 92 wt. %, or at least about 93 wt. %, or at leastabout 94 wt. %, or at least about 95 wt. %, or at least about 96 wt. %,or at least about 97 wt. %, or at least about 98 wt. %, or at leastabout 99 wt. % of the total weight of aggregate originally present inroofing shingles 202 is recovered as aggregate product 210.

As described above, the asphalt/fiber slurry 226 may be removed from theupper end of the separation tank 222. The upper end of the separationtank 222 may have a tapered frustoconical shape such that theasphalt/fiber slurry 226 is channeled towards the central upper end ofthe separation tank 222 for easier removal.

The recovery of asphalt and fiber in the asphalt/fiber slurry 226 fromthe separation tank 222 may be highly efficient such that the wt. ratioof asphalt to fiber in the asphalt/fiber slurry 226 is similar to thewt. ratio in the roofing shingles 202, i.e., about a 1:1 wt. ratio ofasphalt to fiber. The asphalt/fiber slurry 226 also includes aproportion of fluid. According to an embodiment in which the fluid iswater, the asphalt/fiber slurry 226 can contain at least about 80 wt. %water, based on the total weight of the asphalt/fiber slurry forexample, at least about 81 wt. % water, at least about 82 wt. % water,at least about 83 wt. % water, at least about 84 wt. % water, at leastabout 85 wt. % water, at least about 86 wt. % water, at least about 87wt. % water, at least about 88 wt. % water, at least about 89 wt. %water, at least about 90 wt. % water, at least about 91 wt. % water, atleast about 92 wt. % water, at least about 93 wt. % water, at leastabout 94 wt. % water, at least about 95 wt. % water, based on the totalweight of the asphalt/fiber slurry.

In another embodiment not shown in FIG. 2 , the removal of aggregatefrom roofing shingles 202 and the separation of aggregate andasphalt/slurry 226 may occur in separate locations. For example, roofingshingles 202 may first enter a first tank where contact with one or morestreams of fluid 224 occurs in order to separate aggregate in a similarmanner as described above. In this embodiment, separation of aggregatefrom asphalt/fiber slurry 226 does not occur in the same tank wherecavitation occurs. Instead, a mixture of aggregate, asphalt/fiber slurry126 and fluid may feed into a separation apparatus in fluidcommunication with the first tank, where separation of aggregate product210 from asphalt/fiber slurry 226 occurs. The separation apparatus maybe any suitable apparatus operable to separate aggregate fromasphalt/fiber slurry 226 such as a separation tank, a vertical orhorizontal classification tank or a jig concentrator.

In an embodiment, the separation apparatus may be a jig such as a wateror an air pulsed jig. A water jig may include an inclined jig bed (suchas a screen or sieve) within a tank of fluid, such as fluid 224. Astream of aggregate and asphalt fiber slurry 226 may be fed on top ofthe jig bed at the higher end of the inclined jig bed. The fluid withinthe tank may be pulsed such that a column of fluid rises up through thejig bed, suspending the particles (e.g. the aggregate and asphalt/fiberparticles) within the column of fluid. When the fluid level drops backdown, the particles will be redeposited onto the jig bed. As the pulsingof the fluid is repeated, those particles with a higher specific gravity(i.e., aggregate) will redeposit faster than those particles with alower specific gravity (i.e., asphalt/fiber). As such, the aggregate andasphalt/fiber will be separated by density and can be extracted fromlower end of jig bed separately.

Referring to FIG. 2 the asphalt/fiber slurry 226 that is recovered fromthe separation tank 222 is sent to and received by a dewatering ordrying apparatus 228 where fluid is removed from the asphalt/fiberslurry 226 to produce the asphalt/fiber mixture 212. Such removal cannot only increase process efficiency but can also reduce sludge and/oremulsion formation from possibly occurring in subsequent steps 106 and108 of method 100.

The dewatering or drying apparatus 228 may be any suitable type of dryerequipment operable for removing a proportion of fluid from theasphalt/fiber slurry 126. For example, the drying apparatus 228 may be avacuum dryer, tray dryer, fluidized bed dryer, rotary dryer, dewateringscreen or spray dryer. In another embodiment, the drying apparatus 228is a centrifuge, for example a decanter centrifuge. The use of adecanter centrifuge may be preferred since it is able to operate at ahigh throughput while at ambient temperature. In still anotherembodiment, the drying apparatus 228 may be a hydrocyclone. Theasphalt/fiber slurry 226 may first enter the hydrocyclone where a firstproportion of the fluid from the asphalt/fiber slurry 226 is removed,for example from about 70-95 wt. % of the total weight of fluid presentin asphalt/fiber slurry 226 is removed. The drying apparatus 228 mayfurther include a secondary drying apparatus, such as a fluidized beddryer located downstream of the hydrocyclone, where a second proportionof fluid is removed from the asphalt/fiber slurry.

In some embodiments, the fluid that is removed from the asphalt/fiberslurry 226 by the drying apparatus 228 may be recovered and recycledback to the separation tank 228. When the fluid that is removed iswater, such water may be treated to remove impurities before beingrecycled back to the separation tank 222. For example, suspended solidsin the water may be removed using a de-silter prior to being recycledback to the separation tank 222.

The dewatering or drying apparatus 228 may be configured and operable toremove only fluid from the asphalt/fiber slurry 226 and thus,substantially all of the asphalt and fiber in the asphalt/fiber slurry226 may be recovered as asphalt and fiber in the asphalt/fiber mixture212. In an embodiment, more than 80 wt. % of the total weight of asphaltand fiber in the asphalt/fibre slurry 226 is recovered as asphalt andfiber in the asphalt/fiber mixture 212, or more than 85% wt. %, or morethan 90% wt. %, or more than 95% wt. %, or more than 98% wt. % of thetotal weight of asphalt and fiber in asphalt/fibre slurry 226 isrecovered as asphalt and fiber in the asphalt/fiber mixture 212.

Generally speaking, the asphalt/fiber mixture 212 will have a fluidcontent that is less than the fluid content of the asphalt/fiber slurry226. According to one embodiment, when the fluid is water, theasphalt/fiber mixture 112 can contain less than about 1 wt. % water,based on the total weight of the asphalt/fiber mixture, for example,less than about 2 wt. % water, or less than about 4 wt. % water, or lessthan about 6 wt. % water, or less than about 8 wt. % water, or less thanabout 10 wt. % water, or less than about 12 wt. % water, or less thanabout 14 wt. % water, or less than about 15 wt. % water, based on thetotal weight of the asphalt/fiber mixture.

As described above, substantially all of the aggregate may be separatedfrom the roofing shingles 202, such that the asphalt/fiber mixture 212is substantially free of aggregate. In one embodiment, the asphalt/fibermixture may contain less than about 5 wt. % of aggregate, based on thetotal weight of the asphalt/fiber mixture. In other embodiments, theasphalt/fiber mixture may contain less than about 4 wt. %, or less thanabout 3 wt. %, or less than about 2 wt. %, or less than about 1 wt. %,based on the total weight of the asphalt fiber mixture. Accordingly, theaggregate removal unit 204 may be operable to remove at least 95 wt. %of the total weight of aggregate in the roofing shingles 202. In otherembodiments, the aggregate removal unit 204 may be operable to remove atleast about 96 wt. %, or at least about 97 wt. % or at least 98 wt. % orat least 99 wt. % of the total weight of aggregate in the roofingshingles 202.

Separation of Fiber Step (106) in Fiber Separation Unit (206)

As described above, in step 106, fiber may be separated from theasphalt/fiber mixture 112 by adding a solvent 114 to the asphalt/fibermixture 112 to form the asphalt/fiber/solvent slurry 134 and machinepressing the slurry to remove fiber from the slurry to produce anasphalt/solvent mixture 118 and a fiber product 116. In the embodimentshown in FIG. 2 , this separation may be accomplished in the fiberseparation unit 236 by adding solvent 230 to the asphalt/fiber mixture212 in mixing tank 232 to form an asphalt/fiber/solvent slurry 234 andseparating fiber from the asphalt/fiber/solvent slurry 234 in the fiberseparator 236 to produce an asphalt/solvent mixture 216 and fiberproduct 214. In one embodiment, step 106 is performed in the fiberseparation unit 206 at ambient temperature.

The mixing tank 232 may be any suitable container or vessel configuredto receive and mix the solvent 230 and asphalt/fiber mixture 212 to formthe asphalt/fiber/solvent slurry 216 and holding the slurry therein. Themixing tank 232 may include any mixing device suitable for mixingdescribed above, such as a paddle, impeller or a recirculation pump toimprove the contact between the solvent 230 and asphalt/fiber mixture212.

The solvent 230 may be any suitable solvent or blend of more than onesolvent. In one embodiment, the solvent 230 may be at least one solventthat is miscible with asphalt. The solvent 230 may perform some or allof the beneficial functions as outlined below when introduced into themixing tank 232. Firstly, the solvent 230 may act as a release agent tostrip or remove asphalt coating the fiber in the asphalt/fiber mixture212 (i.e. the fiber in the asphalt/fiber/solvent slurry 134 may becomesubstantially free from adhered asphalt). The solvent 230 may also actas a co-solvent/diluent for the asphalt/fiber mixture 212 which willbeneficially reduce the viscosity of the asphalt/fiber/solvent slurry234. As such, the asphalt/fiber/solvent slurry 234 may include a liquidphase that is a solution of solvent and asphalt with a solid phase offiber. Furthermore, the solvent 230 may be selected from a group ofsolvents having a boiling point that enables easier solvent separationin step 108.

In one embodiment, the solvent 230 may comprise an aromatic solvent,which refers to a solvent comprising at least one aryl group. The term“aryl” as used herein, whether it is used alone or a part of anothergroup refers to cyclic groups that contain at least one aromatic ring.In an embodiment, the aromatic solvent is benzene, toluene,ortho-xylene, meta-xylene, para-xylene, ethylbenzene ortrimethylbenzene.

In another embodiment, the solvent 230 comprises an aliphatic solvent orblend of more than one aliphatic solvent such as a straight or branchedchain C₄-C₃₀ alkane or C₄-C₄₀ olefin. In one embodiment, the aliphaticsolvent, is butane, pentane, cyclopentane, hexane, cylcohexane, heptane,octane, nonane, decane, undecane or dodecane, or a terpene such aslimonene. In other embodiments the aliphatic solvent may be any suitableblend of more than one aliphatic solvents such as gasoline, diesel,petroleum distillate, petroleum ether, mineral spirits, naptha, keroseneor turpentine.

In another embodiment, the solvent 230 comprises a halogenated solvent,that is a solvent containing at least one halogen atom, such asdichloromethane, 1,1,1-trichloroethylene, tetrachloroethylene,n-propylbromide, chlorohexane, carbon tetrachloride or chloroform.

In another embodiment, the solvent 230 comprises a suitable alcohol,such as a straight or branched chain C₁-C₁₀ alcohol or mixture thereof.In an embodiment the C₁-C₁₀ alcohol is ethanol, butanol, propanol,isopropanol (IPA). The alcohol may comprise an aromatic alcohol, whichrefers to an alcohol comprising an aryl group as defined above, such asbenzyl alcohol.

In an embodiment, the solvent 230 comprises an ether, such astetrahydrofuran, diethyl ether, 1,2-dioxane, 1,3-dioxane or 1,4-dioxane,methoxybenzene.

In another embodiment, the solvent 230 comprises a ketone, for example aC₃-C₁₂ ketone such as acetone, methyl ethyl ketone (MEK), methylisobutyl ketone, or methyl acetate.

In another embodiment, the solvent 230 is carbon disulfide.

The solvent 230 may be added to the mixing tank 232 in any suitable massfraction relative to the asphalt/fiber mixture 212. For example, themass fraction of solvent 230 that is added to the asphalt/fiber mixture212 may be selected such that substantially all of the asphalt in theasphalt/fiber mixture 212 coating the fiber is released so substantiallyall of the asphalt in the asphalt/fiber/solvent slurry 234 is in theliquid phase. Further, the solvent 230 may be added such that theasphalt/fiber/solvent slurry 234 is flowable at ambient temperature.

In one embodiment, the mass fraction of solvent 230 added to theasphalt/fiber mixture may be in the range of about 15-50 wt. % relativeto the total weight of the asphalt/fiber mixture 212. In anotherembodiment, the amount of the solvent 230 added to the asphalt fibermixture is an amount of greater than about 15 wt. % relative to totalweight of the asphalt/fiber mixture 212, for example, greater than about20 wt. %, greater than about 25 wt. %, greater than about 26 wt. %,greater than about 27 wt. %, greater than about 28 wt. %, greater thanabout 29 wt. %, greater than about 30 wt. %, greater than about 31 wt.%, greater than about 32 wt. % greater than about 33% water, greaterthan about 34 wt. % water, greater than about 35 wt. % water, greaterthan about 40 wt. % water, greater than about 45 wt. % water, or greaterthan about 50 wt. %, relative to the total weight of the asphalt/fibermixture 212.

The asphalt/fiber/solvent slurry 234 is then sent to and received by thefiber separator 236 to separate the fiber from the slurry. The fiberseparator 236 may be any suitable piece of equipment or apparatus thatis operable to separate fiber from the asphalt/fiber/solvent slurry 234,such as a machine press (mechanical press) or a filter press. Forexample, the fiber separator 236 may be a rotary press, belt press,hydraulic press, piston press, hydrocyclone or a centrifuge.

In one embodiment, the fiber separator 236 is a screw press, alsocommonly referred to as a dewatering screw press, which is operable toseparate fiber from the asphalt/fiber/solvent slurry 234. The screwpress is known and may include one or more screws (also known as anArchimedean screw) which is rotatable within a housing. The screw mayinclude a central shaft about which is wound a spiral steel plate.Material, in this case the asphalt/fiber/solvent slurry 234, may be sentto and received by an inlet of the screw press. As the screw rotates,for example when driven by an electrical motor, the slurry 234 withinthe housing will move towards the opposite end of the inlet (i.e.,discharge end) of the housing. As the slurry 234 moves from the inletend to the discharge end, the cavity size in which the slurry 234 iscontained decreases such that the slurry therein is compressed. Thisreduction in cavity size may be due to a taper on the central shaft ofthe screw such that the diameter of the shaft increases towards thedischarge end. Additionally or alternately, the separation between theflights of the spiral steel plate may decrease towards the discharge endof the screw press in order to compress the slurry 234 between theflights towards the discharge end.

The housing may be made from a permeable material, such as a screenedsurface, a perforated sheet, a sintered screen or a wedge wire screenthat, as the slurry 234 is compressed therein, the internal pressuregenerated within the housing forces asphalt and solvent to be dischargedthrough the permeable material. The permeable material may be selectedsuch that substantially only asphalt and solvent will pass through thepermeable material and not fiber or other solid particles from theasphalt/fiber/solvent slurry 234. In this example, the liquid (orfiltrate or liquor) passing through the permeable material is theasphalt/solvent mixture 216.

The remaining solid fiber material, which does not pass through thecylindrical housing is conveyed towards the discharge end of the screwpress by the rotational action of the screw and may be recovered at thedischarge end as the fiber product 214 commonly called the press cake orfilter cake.

In comparison to other fiber separators, a screw press is well suited toprocess relatively viscous materials, such as the asphalt/fiber/solventslurry 234. A screw press may also advantageously operate in continuousmanner with a high throughput and is less susceptible toclogging/blockages in comparison to other fiber separators.

In some embodiments, either or both of the screw press or theasphalt/fiber/solvent slurry 234 may be at ambient temperature or at anelevated temperature.

In and embodiment the screw press may be a twin screw press, whichincludes two opposed, intermeshing screws configured to rotate inopposite directions relative to each other.

The fiber product 214 that is separated from the slurry 234 andrecovered from the fiber separator 236 may be substantially free ofasphalt. In one embodiment, the fiber product 214 may have less thanabout 20 wt. % of asphalt, based on the total weight of the fiberproduct 214. In other embodiments, the fiber product 214 may have lessthan about 15 wt. %, or less than about 10 wt. % or less than about 9wt. % or less than about 8 wt. % or less than about 7 wt. % or less thanabout 6 wt. % or less than about 5 wt. % or less than about 4 wt. % orless than about 3 wt. % or less than about 2 wt. % or less than about 1wt. % of asphalt, based on the total weight of the asphalt product 214.

Recovery of Asphalt Step (108) in Solvent Separation Unit (208)

As described above, in step 108 solvent may be separated from theasphalt/solvent mixture 116 by heating the mixture to separate thesolvent from the mixture to produce an asphalt product 118. In theembodiment shown in FIG. 2 , this separation may be accomplished in thesolvent separation unit 208 by passing the asphalt/solvent mixture 216through the solvent separator 238 to produce the asphalt product 218.

In one embodiment, the solvent separator 238 may be any suitabledistillation unit or evaporator such as, for example a fractionaldistillation unit, a short path distillation unit, a 2-stagedistillation unit, a disc and donut distillation unit or a spinning banddistillation unit operable to separate solvent from the asphalt/solventmixture 216. The solvent separator 238 may operate at atmospheric orreduced pressure as required. In another embodiment, the solventseparator 238 may be an evaporator, such as thin film evaporator, whichmay include a falling film evaporator or a wiped film evaporator. Inanother embodiment, the solvent separator 238 may be a heated stirredtank such as a commonly known continuous stirred tank reactor (CSTR).

In other embodiments, the solvent separator operates at atmosphericpressure and at a temperature of about 75° C. or greater. In oneembodiment, the solvent separator operates at atmospheric pressure and atemperature of about 77° C.

In one preferred embodiment, the solvent separator 238 is a wiped filmevaporator (WFE), also known as a wiped film distillation unit. The WFEmay include a vertically orientated cylinder with an internal rotordriven wiper. The wiper may include a single blade or a plurality ofstacked blades that may be offset and/or overlap with respect to eachother. In an embodiment the WFE may have 32 blades. The cylinder may beexternally heated, such as by a surrounding heated jacket. Theasphalt/solvent mixture 216 may be introduced at the upper end of thecylinder and the wiper may distribute the mixture to create a thin filmof the mixture on the inner surface of the cylinder. As the mixture 216spirals down the inner surface of the cylinder, the solvent within themixture is readily evaporated.

The distillate vapor (i.e., solvent) may be condensed and collected inan internal condenser running down the center of the cylinder. In otherembodiments, the distillate vapor may flow out of either the top orbottom of the WFE and may be condensed in an external condenser.

The concentrate (i.e., asphalt 118) does not evaporate under theseconditions and will run down the inner surface of the cylinder and berecovered as the asphalt product 218 at the lower end of the cylinderwhere it may be transferred, for e.g., to a storage tank or rail car orroad tanker, for further processing/repurposing.

The WFE may operate at about 10° C. to about 50° C. above the boilingpoint of the solvent being used and at about 10° C. to about −50° C.below the lowest boiling point component of the asphalt. The WFE mayoperate under a vacuum which may be least about 0 mmHg up to a slightpositive pressure of about 30 psia (i.e., from about 0 atm to about 2atm). In one example embodiment, when the solvent 230 is toluene, theWFE may operate at a temperature of about 155-165° C. and at atmosphericpressure.

In an embodiment, the WFE operates at a temperature between about 120°C. and about 200° C. and at atmospheric pressure.

The solvent that is condensed and recovered from the solvent separator236 may be substantially free of asphalt and other impurities and may berecycled back to mixing tank 232, as shown in FIG. 2 .

The asphalt product 218 may be recovered from the solvent separator 238in high yield and purity and may be substantially free of fiber, solventand fluid 224. According to one embodiment, the asphalt product 218 cancontain less than about 1 wt. % of fiber and/or solvent and/or fluid224, based on the total weight of the asphalt product, for example lessthan about 2 wt. %, less than about 3 wt. %, less than about 4 wt. % orless than about less than about 5 wt. %, based on the total weight ofthe asphalt product.

In an embodiment where asphalt/solvent mixture 216 contains a proportionof water and where solvent 230 is toluene, the toluene and water withinasphalt/solvent mixture 261 may form an azeotropic mixture. As is known,an azeotropic mixture may have a boiling point that is lower than eitherof its constituents. As such, depending on the composition of theazeotropic mixture the solvent separator 238 (such as a WFE) may operateat a lower temperature.

The overall recovery of the asphalt product 218 from the roofingshingles 202 may be highly efficient such that a large proportion of theasphalt that was present in the roofing shingles 202 when the roofingshingles are added to the separation tank 222 is recovered as asphaltproduct 218. According to one embodiment, at least about 80 wt. % of thetotal weight of asphalt in the roofing shingles 202 is recovered asasphalt product 218, for example at least about 82 wt. %, at least about84 wt. %, at least about 86 wt. %, at least about 88 wt. %, at leastabout 90 wt. %, at least about 92 wt. %, at least about 94 wt. %, atleast about 96 wt. %, at least about 98 wt. % at least about 98 wt. % ofthe total weight of asphalt in the roofing shingles 202 is recovered asasphalt product 218.

In another embodiment, the present disclosure provides a process forrecycling asphalt-based roofing materials wherein the units of such aprocess are completely integrated, and thus the process is of low cost,economical and versatile due to the alternatives and interconnectionswithin their steps. The integrated process is more energy efficient andmaterials efficient than the individual processes together, and, assuch, yields a higher productivity.

According to one embodiment, the integrated process of the presentdisclosure relates to an integrated process for recycling asphalt-basedroofing shingles to produce an aggregate product, a fiber product and anasphalt product. The integrated process may include a step of contactingthe asphalt-based roofing shingles with at least one pressurized streamof fluid in a separation tank to separate aggregate from the roofingshingles to produce an asphalt/fiber slurry and the aggregate product asdescribed above. Moisture is then removed from the asphalt/fiber slurryin a dewatering or drying apparatus to produce an asphalt/fiber mixture.The moisture that is removed in the drying apparatus may be recoveredand recycled back to the separation tank.

The integrated process also includes a step of adding a solvent to theasphalt/fiber mixture produced above in a mixing tank to produce anasphalt/fiber/solvent slurry. Fiber is separated from theasphalt/fiber/solvent slurry in a fiber separator to produce anasphalt/solvent mixture and the fiber product.

The integrated process also includes a step of separating solvent fromthe asphalt/solvent mixture produced above in a solvent separator toproduce the asphalt product. Solvent separated from the asphalt/solventmixture may be recovered and recycled back to the mixing tank.

The integrated process described above may run batch-wise orcontinuously where roofing shingles are continuously added to theprocess while the aggregate, fiber and asphalt products are continuouslyproduced and collected. The fluid and solvent that are recovered may becontinuously reused within the integrated process as described abovesuch that additional fluid and solvent may not need to be required to beadded during continuous operation. In some embodiments a small amount offluid and/or solvent may need to be added to account for any lossesduring the process.

Accordingly, the products made in the method, integrated process andsystem described herein may be suitable for a use in variety ofapplications. By way of example, the aggregate product may be used inasphalt concrete for paving and road surfaces, in the manufacture of newasphalt-based roofing materials, as a blasting material (or media) insandblasting and in other general construction materials.

When the roofing shingles include paper fiber, the fiber product mayhave a high BTU value and may be suitable for use as an engineered fuel.The fiber product may beneficially contain a trace amounts ofcombustible organics, such as solvent and/or asphalt which may increasethe BTU value of the fiber product. In one embodiment, the fiber productmay be used as an engineered fuel, such as for a cement productionfacility.

When the roofing shingles include glass fiber, the fiber product may beincorporated into the production of new glass fiber materials andproducts. In another embodiment, the fiber product may be used inpatching kits for repairing fiber glass structures, such as boats andkayaks. In one embodiment, the fiber product may be further processed bymechanical grinding or milling to reduce its particle size to a finepowder that may be incorporated as a filler or reinforcing material forproducts such as artificial wood, cement or asphalt concrete.

The asphalt product produced herein may be of a similar quality torefined (or virgin) asphalt and may be suitable for any applicationwhere refined asphalt is used. For example, the asphalt may be suitablefor blending with virgin asphalt for any application where refinedasphalt is used. For example, the asphalt product may be used in asphaltconcrete for paving and road surfaces, in the manufacture of newasphalt-based roofing materials and sealing and insulating a variety ofbuilding materials, such as pipe coatings and carpet tile backing.

In an embodiment, the asphalt produced herein may have a penetrationgrade of between about 8 and about 50 decimillimeters (dmm), as measuredby the American Society for Testing and Materials (ASTM) D5-06 standardtest method.

In an embodiment, the asphalt produced herein may have a softening pointof between about 80° C. and about 120° C. or greater as measured by theASTM D36-95 standard test method.

In an embodiment, the asphalt produced herein may have a flash point ofbetween about 180° C. and about 300° C. or greater as measured by theASTM D92-05a standard test method.

In other embodiments, any of the intermediate products disclosed herein,such as the asphalt/fiber slurry, the asphalt/fiber mixture, theasphalt/fiber/solvent slurry and the asphalt/solvent mixture, may becollected and transported to another location for further processing,which may include the steps described above or different method steps toproduce any of the product described above.

For example, in one embodiment, the asphalt/solvent mixture, rather thanentering the solvent separator, may be transported, such as by tankertruck, rail or pipeline for further use, storage or processing. Thepresence of the solvent in the mixture may beneficially act as a diluentto lower the viscosity of the asphalt/solvent mixture simplifying thehanding and transport of the mixture, especially while at lowertemperatures. In one embodiment, the asphalt/solvent mixture may betransported to another facility where the solvent may be separated fromthe mixture by a solvent separator described above to produce an asphaltproduct.

Although making and using various embodiments of the present disclosurehave been described in detail above, it should be appreciated that thepresent disclosure provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of theinvention.

What is claimed is:
 1. A method for recovering an asphalt product froman asphalt/solvent mixture comprising: (a) passing the asphalt/solventmixture through a solvent separator to separate the asphalt product fromthe solvent; and (b) removing the asphalt from the solvent separator,wherein the asphalt in the asphalt/solvent mixture was derived from anasphalt-based roofing material and is substantially free of aggregateand fiber.
 2. The method of claim 1, wherein the solvent separator is adistillation unit or evaporator.
 3. The method of claim 2, whereinsolvent separator is a wiped film evaporator.
 4. The method of claim 3,wherein the solvent comprises an aromatic solvent.
 5. The method ofclaim 4, wherein step (a) is performed at a temperature between about50° C. to about 160° C.
 6. The method of claim 1, wherein at least about80 wt. % of a total weight of asphalt originally in the asphalt-basedroofing material is recovered as the asphalt product.
 7. An asphaltproduct produced according to the method of claim
 1. 8. A system forproducing at least an asphalt product from an asphalt-based roofingmaterial containing a plurality of roofing shingles, the systemcomprising: (a) an aggregate removal unit operable to removesubstantially all aggregate from the asphalt-based roofing material toproduce an aggregate-free asphalt/fiber mixture; (b) a fiber separationunit operable to mix the aggregate-free asphalt/fiber mixture with asolvent to produce a slurry and to remove substantially all fiber fromthe slurry to produce an asphalt/solvent mixture; and (c) a solventseparation unit operable to separate substantially all solvent from theasphalt to produce an asphalt product.
 9. The system of claim 8, whereinthe aggregate removal unit comprises a separation tank configured toreceive and combine the asphalt-based roofing material and at least oneor more pressurized streams of a first fluid and to agitate or pulse amixture of aggregate, a second fluid and the aggregate-freeasphalt/fiber mixture.
 10. The system of claim 9, wherein the aggregateremoval unit further comprises a dewatering or drying apparatusconfigured to remove moisture from the asphalt/fiber mixture.
 11. Thesystem of claim 8, wherein the fiber separation unit comprises a mixingtank configured to receive and combine the aggregate-free asphalt/fibermixture and a solvent and produce an asphalt/fiber/solvent slurry. 12.The system of claim 11, wherein the fiber separation unit furthercomprises a fiber separator configured to receive theasphalt/fiber/solvent slurry and separate fiber from theasphalt/fiber/solvent slurry and produce an asphalt/solvent mixture anda fiber product.
 13. The system of claim 8, wherein the solventseparation unit comprises a solvent separator configured to receive theasphalt/solvent mixture and heat the mixture to separate the solventfrom the mixture and produce the asphalt product.
 14. The system ofclaim 13, wherein the solvent separation unit further comprises acondenser configured to recover the solvent separated from the mixture.15. The system of claim 8, further comprising a pretreatment unitcomprising a grinder operable to reduce the particle size of theasphalt-based roofing material and a feed system to deliver theasphalt-based roofing material to the aggregate removal unit.